What happened
The FAA’s narrative, in sentence case. The FAA writes it in capitals and removes private details.
(-23) During a training flight a #1 hydraulics failure was simulated. The aircraft was at 700 feet MSL, 80 knots and 55% torque when the #1 hydraulics system was turned off. The aircraft immediately experienced a violent, ever-increasing yaw excursions. The afcs was disengaged, all lights out, however yaw excursions continued to increase and the aircraft began violent pitch excursions with corresponding roll motion. The #1 hydraulics system was turned back on and the pitching and yawing started to slow down but did not stop. An emergency was declared and the pilot made a slow turn to line up with the runway at which point the t/r pedal felt as though it was stuck in the left pedal position. At approximately 15 feet the helicopter made a 360 degree uncommanded turn and pitched up. As the aircraft came back around the pilot cut power to both engines and set it down hard. Both cross tubes were bent beyond the limitation. No injuries to the pilots.
As the FAA filed it
(-23) DURING A TRAINING FLIGHT A #1 HYDRAULICS FAILURE WAS SIMULATED. THE AIRCRAFT WAS AT 700 FEET MSL, 80 KNOTS AND 55% TORQUE WHEN THE #1 HYDRAULICS SYSTEM WAS TURNED OFF. THE AIRCRAFT IMMEDIATELY EXPERIENCED A VIOLENT, EVER-INCREASING YAW EXCURSIONS. THE AFCS WAS DISENGAGED, ALL LIGHTS OUT, HOWEVER YAW EXCURSIONS CONTINUED TO INCREASE AND THE AIRCRAFT BEGAN VIOLENT PITCH EXCURSIONS WITH CORRESPONDING ROLL MOTION. THE #1 HYDRAULICS SYSTEM WAS TURNED BACK ON AND THE PITCHING AND YAWING STARTED TO SLOW DOWN BUT DID NOT STOP. AN EMERGENCY WAS DECLARED AND THE PILOT MADE A SLOW TURN TO LINE UP WITH THE RUNWAY AT WHICH POINT THE T/R PEDAL FELT AS THOUGH IT WAS STUCK IN THE LEFT PEDAL POSITION. AT APPROXIMATELY 15 FEET THE HELICOPTER MADE A 360 DEGREE UNCOMMANDED TURN AND PITCHED UP. AS THE AIRCRAFT CAME BACK AROUND THE PILOT CUT POWER TO BOTH ENGINES AND SET IT DOWN HARD. BOTH CROSS TUBES WERE BENT BEYOND THE LIMITATION. NO INJURIES TO THE PILOTS.